Stamping device



June 27, 1967 A, DIESEL 3,327,623

STAMPING DEVICE Filed March 30, 1964 //5 MAC.

ATTORNEYS.

United States Patent O 3,327,623 STAMPING DEVICE Arthur Diegei, 11219 Jasper Ave., Edmonton, Alberta, Canada Filed Mar. 30, 1964, Ser. No. 355,728 2 Claims. (Cl. 101-18) This invention relates to stamping devices and, more particularly, to portable electrically operated stamping devices suitable for producing a stamped impression on metal workpieces.

Although portable stamping devices are known, the known devices are so constructed that their yaccidental operation is possible and even probable and in this respect they are unsatisfactory. In general, known portable stamping devices, particularly those which are electrically operated, are actuated safely by means of a button or trigger which is depressed by the nger of the operator. It will be readily apparent that accidental operation of the device will result whenever the button or trigger is depressed accidentally through contact with an object, or through accidental contact by the operator. Such `accidental operation may easily result in injury to the operator or, if the device is actuated prematurely through accidental contact by the operator, the result maybe to spoil the appearance or designation of workpieces which have been stamped accidentally in the wrong place.

I have found that this deficiency in known devices may be overcome by providing a stamping device, comprising a generally hollow elongated body, a plurality of typebars having type-faces thereon, means for selectively positioning a type-bar at one end of said body with its typeface outwardly directed, a tiring pin slidably fitted Within said body, resilient means urging one end of said riug pin toward said one end of said body and against a positioned type-bar, a normally open safety switch lclosable upon movement of said firing pin inwardly of said body in response to pressure exerted by said type-bar when pressed against an object to be stamped, a striking ram located within said body and movable against the end of said firing pin remote from said type bar, resilient means urging said striking ram laway from said firing pin, and means to actuate said striking ram upon closure of a manually operable switch contemporaneously with closure of said safety switch. Such a stamping device must rst be pressed 4against the work piece to operate the safety switch and, when the safety switch is closed, the manually operable switch must then be closed before the device will be actuated. The operation either switch by itself will not actuate the device so that the likelihood of accidental operation is reduced to negligible proportions.

In drawings which illustrate an embodiment of the invention, FIGURE 1 is `a cross section of a stamping device in accordance with the invention, FIGURE 2 is a detailed section of the safety switch mechanism in the device of FIGURE l, FIGURE 3 is a diagrammatic representation of the electrical circuit employed in the device of FIGURE 1, and FIGURE 4 is an end View of the head of the stamping device of FIGURE 1.

Referring now to FIGURE 1, the stamping device consists of a generally hollow cylindrical exterior casing 1, a pistol grip handle 2 aixed to one end thereof and carrying a spring biased actuating trigger 3, and a hollow coneshaped head 4 mounted on the other end of the cylindrical body 2 and coaxial therewith.

The exterior surface of casing 1 including head 4 is bisected =by a groove 5 which passes over the apex of the cone shaped head. Slidably located within the groove 5 is an endless flexible belt 6 to which are removably secured a plurality of type-bars '7 with type-faces 10 out- ICC wardly directed. The type-bars are snugly received in apertures in the belt (not shown in the drawings), and are there retained by enlarged heads 11 which abut against the inner surface of the belt and the base of groove 5 when the belt is in position.

Tension on belt 6 is maintained by means of shoe 12 which is outwardly biased under the pressure exerted by coil spring 13. The coil spring 13 is housed within a tubular guide member 14 which is threadedly secured in the center of one end of casing 1 as at 15 and which projects into the hollow interior of the casing and is coaxial therewith. Spring 13 is interposed between an annular shoulder 16 in guide 14 and the'inner face of shoe 12 and is guided between the inner surface of guide 14 and stem 17 of shoe 12. The belt may be moved along the groove 5 to position any type-bar at the apex of the cone shaped head, yby manipulation of the thumbpiece 18 which is atiixed thereto.

Located within the hollow portion of conical head 4, and rigidly held in place between annular shoulder 21 and locking washer 22 is the safety switch mechanism indicated generally at 20. The safety switch mechanism 20, as will be seen more particularly in FIGURE 2, is composed of three abutting washer like members 23, 24 and 25, having corresponding bores 26 therethrough. The washer like member 23 is provided with an annular rim 27 about bore 26. Threadedly mounted in washer like member 23 is a plug 30 which projects into a bore 31 of the washer like member 24 and, Slidably mounted in the plug 30 is a pin 32 having a conical shaped head 33 and annular flange 34 at the base of head 33. The ange 34 is normally pressed against plug 30 by the pressure of compression spring 35 which is interposed between a ange 36, near the end of pin 32, and plug 30. Washer like member 25 is provided with a bore 37, co-extensive with the bore 31 in washer like member 24, and on either side of this bore are located contacts 4d which extend into the path of conical head 33 when the latter is moved toward them.

Referring again to FIGURE l, a tiring pin 41 is axially an-d Slidably mounted in conical head 4. The firing pin 41 is provided with an annular ange 42 which is normally urged against inner face 43 of conical head 4 by means of a compression spring 44 interposed between flange 42 and safety switch assembly 20. It will also be seen that under the action of spring 44, the end face 45 of the firing pin 41 is normally maintained in Contact with the enlarged head of a type-face 7 which is positioned at the apex of conical head 4.

Located within the cylindrical casing 1, and 4retained in place by locking washer 46, is solenoid coil 47, and slidably mounted within the solenoid coil is a striking ram having a stern portion `51 andan enlarged head portion 52. The head portion of the striking ram is normally biased against an adjustable stop S3 which is threadedly mounted in the casing 1 Vby means of compression spring 54 interposed between locking washer 22' and flange 54 on stem portion 51. To assist in the alignment of the striking ram, the head portion 52 is provided with an axial bore 55 adapted to receive guide 14. The intermediate portion of the striking ram is of magnetic material and forms a core for the coil such that when the coil is energized, the striking ram will be forced to move axially towards the firing pin. The tip of the stem portion 51 of the striking ram will preferably be of hardened material, `as will the inner end of tiring pin 41, since these two members come into forceable contact `when the solenoid coil is energized.

The trigger 3 is Slidably retained in pistol grip handle 2 upon a holding pin 57 and is normally `biased outwardly -under the action of spring 56. Mounted in the pistol grip handle, adjacent the trigger 3, is switch 60 having a fixed contact 61 and a movable contact 62 associated therewith. The movable contact 62 is normally out of engagement with contact 61. However, when the trigger 3 is slid inwardly of the handle under the pressure of the finger of an operator, a face of trigger 3 forces movable contact 62 into engagement with contact 61 to close switch 60.

For the sake of clarity and ease of comprehension, the Wiring and electrical circuitry is illustrated schematically in FIGURE 3 of the drawings. However, in practice, the wiring pass through suitable insulated conduits in the casing and a number of the 4components of the circuitry will be housed in the handle of the device. Where portions of the electrical circuitry also form a part of the mechanical apparatus previously described, as in the case of the switches and the solenoid coil, common reference numerals have been used. The circuit comprises a capacitor 63, a resistor 64 and -rectier 65 connected in series across a 115 volt A.C. source. One terminal of the source is connected directly to the cathode of silicon controlled rectifier 66 and also through capacitor 63, switches 33-40 and 62-61 and resistor 67 to the gate lof the silicon controlled rectifier 66. The silicon controlled rectier is connected in series with solenoid coil 47 across the source. In operation, capacitor 63 charges up through rectifier 65 and resistor 64. When switches 33-40 and 62-61 are closed, capacitor 63 discharges through resistor 67 and the silicon controlled rectifier, switching it to the conducting state. The circuit is so designed that the silicon controlled rectifier will pass pulsating DC. with an average value of about 8 amperes through the solenoid coil 47. Within about one fifteenth of a second the discharge current of capacitor 63 will have decreased sufficiently to block the silicon control rectifier. By blocking the silicon control rectifier after one fifteenth of a second, firing is assured by resistor 64 which will limit the charging current into capacitor 63 to less than the minimum current required to gate the silicon control rectifier. After opening switches 33-40 and 62-61, capacitor 63 will charge up for the next firing within approximately two seconds.

Having referred to the electrical portion of the apparatus, the operation of the apparatus will now be described in conjunction with FIGURE 1. By manipulation of the thumbpiece 1S and the belt 6 in groove 5, a desired type-face 10 is positioned at the apex of the conical shaped head 4 as illustrated by the type-bar 7 in FIGURE l. The type-bar 7 is then pressed against a work piece and this pressure is transmitted directly to the firing pin 41 with the result that it is moved inwardly of the head 4 against the resistance of compression spring 44. As the firing pin 41 moves inwardly, flange 42 whose path of movement intercepts pin 32, contacts the end of pin 32, forcing it inwardly against spring 35 with the result that head 33 bridges the contacts 40 and an electrical circuit is completed through these contacts. The device is then ready to be actuated lby the user who presses trigger 3, closing switch 60and 4by virtue of the contemporaneous closure of safety switch 33-40, permitting the current to iiow to the solenoid coil 47 as described in connection with FIGURE 3. When the solenoid coil is energized, the striking ram 50 is forced towards the apex of conical head 4, sharply contacting the flanged end of firing pin 41 and, in turn, forcing the firing pin against the inner end of type-bar 7 resulting in the impression of type-face 10 on the work piece. Switches 33-40` and 60 are then opened and, under the action of compression springs 44 and 53, the firing pin 41 and the striking ram 50 are returned to their original positions in preparation for another operation.

What I claim as my invention is:

1. A portable electric stamping device comprising a generally hollow cylindrical body having a cone shaped head extending `axially from one end thereof and a pistol grip handle projecting from'the opposite end, a groove encircling the outside of said cylindrical body parallel to its longitudinal axis and passing over the apex of said cone shaped head, an endless flexible belt slidable within said groove, means for tensioning said belt, a plurality of type-bars having type-faces thereon removably mounted on said 4belt so that an elected type-bar may be selectively positioned at the apex of. said cone shaped head with its type-face outwardly directed, a firing pin axially and slidably tted within said cone shaped head, a compression spring urging one end of said firing pin toward the apex of the cone shaped head and against -an elected typeJbar, a normally open safety switch closable on axial movement of said firing pin inwardly of said body in response to pressure exerted by said elected type-bar when pressed against an object to be stamped, a solenoid within said cyclindrical body having its longitudinal axis coincidental therewith a striking ram passing axially through said solenoid and movable against said firing pin upon energization of said solenoid, a return spring urging said striking ram away from said firing pin, an adjustable stop to vary the distance `between said striking ram and said firing pin, a manually operable switch in said pistol grip handle, and means for momentarily energizing said solenoid upon contemporaneous closure of said safety switch and said manually operable switch.

2. A portable electric stamping device, comprising a generally hollow cylindrical body, aV shallow groove longitudinaly lbisecting the surface of said body, an endess flexible belt movable in said groove and having a plurality of type bars with type faces thereon removably mounted therein for selectively positioning a type-bar at one end of said body with its type face outwardly directed, a firing pin axially and slidably fitted within said body, resilient lmeans urging one end of said tiring pin towards said one end of said body and against a type bar positioned there, an annular ange 0n the other end of said firing pin, a normally opened safety switch located in the path of movement of said annular ange and closeable upon movement of said firing pin and said ange inwardly of said body in response to pressure exerted by said type-bar when pressed against an object to be stamped, a striking ram axially located within said cylindrical body and movable against the end of said firing pin remote of said type-bar, resilient means urging said striking ram away from said firing pin, and means to actuate said striking ram upon closure of a manually operable switch contemporaneously with closure of said safety switch.

References Cited UNITED STATES PATENTS 946,267 1/1910 Paulero 173-119 1,042,210 10/1912 Ferris 101-3 1,634,623 7/1927 Miller 173--13 2,281,763 5/1942 Grant 101-287 2,801,583 8/1957 Loushay.

3,012,499 12/1961 Amada lOl-93 3,254,595 6/1966 Sparrow et al. 101-93 ROBERT E. PULFREY, Primary Examllner.

P. R. WOODS, Assistant Examiner. 

1. A PORTABLE ELECTRIC STAMPING DEVICE COMPRISING A GENERALLY HOLLOW CYLINDRICAL BODY HAVING A CONE SHAPED HEAD EXTENDING AXIALLY FROM ONE END THEREOF AND A PISTOL GRIP HANDLE PROJECTING FROM THE OPPOSITE END, A GROOVE ENCIRCLING THE OUTSIDE OF SAID CYLINDRICAL BODY PARALLEL TO ITS LONGITUDINAL AXIS AND PASSING OVER THE APEX OF SAID CONE SHAPED HEAD, AN ENDLESS FLEXIBLE BELT SLIDABLE WITHIN SAID GROOVE, MEANS FOR TENSIONING SAID BELT, A PLURALITY OF TYPE-BARS HAVING TYPE-FACES THEREON REMOVABLY MOUNTED ON SAID BELT SO THAT AN ELECTED TYPE-BAR MAY BE SELECTIVELY POSITIONED AT THE APEX OF SAID CONE SHAPED HEAD WITH ITS TYPE-FACE OUTWARDLY DIRECTED, A FIRING PIN AXIALLY AND SLIDABLY FITTED WITHIN SAID CONE SHAPED HEAD, A COMPRESSION SPRING URGING ONE END OF SAID FIRING PIN TOWARD THE APEX OF THE CONE SHAPED HEAD AND AGAINST AN ELECTED TYPE-BAR, A NORMALLY OPEN SAFETY SWITCH CLOSABLE ON AXIAL MOVEMENT OF SAID FIRING PIN INWARDLY OF SAID BODY IN RESPONSE TO PRESSURE EXERTED BY SAID ELECTED TYPE-BAR WHEN PRESSED AGAINST AN OBJECT TO BE STAMPED, A SOLENOID WITHIN SAID CYCLINDRICAL BODY HAVING ITS LONGITUDINAL AXIS COINCIDENTAL THEREWITH A STRIKING RAM PASSING AXIALLY THROUGH SAID SOLENOID AND MOVABLE AGAINST SAID FIRING PIN UPON ENERGIZATION OF SAID SOLENOID, A RETURN SPRING URGING SAID STRIKING RAM AWAY FROM SAID FIRING PIN, AN ADJUSTABLE STOP TO VARY THE DISTANCE BETWEEN SAID STRIKING RAM AND SAID FIRING PIN, A MANUALLY OPERABLE SWITCH IN SAID PISTOL GRIP HANDLE, AND MEANS FOR MOMENTARILY ENERGIZING SAID SOLENOID UPON CONTEMPORANEOUS CLOSURE OF SAID SAFETY SWITCH AND SAID MANUALLY OPERABLE SWITCH. 